By: Daniel Kaiser, Extension soil fertility specialist While many growers opt for P and K applications in the fall, applying any fertilizer months ahead of when the crop needs it can present some risk for lessening the availability of a nutrient as it has more time to react with the soil. Past AFREC-funded research has shown that spring application of phosphorus resulted in higher corn yield compared to fall application. The next step was to look at whether the same can be said about potassium. Past research has shown that the availability of potassium measured by soil tests does change over time where soil test values are higher in the spring and lower in the summer at points in time where crops are taking up high amounts of potassium. From the perspective of timing, I have not found that the soil test varies in June regardless of whether fertilizer K was applied in the fall or spring. In contrast, soil test phosphorus was almost always less when comparing fall versus spring fertiliz...
By Angie Peltier and Ryan Miller, UMN Extension crops educators, Ryan Huffman, Iowa State University Digital Ag Innovation Lab senior research manager and Jorden Kuntz, founder of Biosphere Drone Solutions Showcasing drones at a field day in northwest Iowa, 2024. Credit: Ryan Huffman. On March 19, 2025, Ryan Huffman, Iowa State University Digital Ag Innovation Lab senior research manager and Jorden Kuntz, founder of Biosphere Drone Solutions, joined UMN Extension crops educator Ryan Miller for a discussion about drones in row crop agriculture. This was the penultimate weekly episode of the 2025 Strategic Farming: Let’s talk crops! webinars. To watch this episode: http://z.umn.edu/StrategicFarmingRecordings ISU Digital Ag Innovation Lab Working as agriculture researchers at a public university typically results in publications in a peer-reviewed journals, where the over-arching goal is to ‘move the ball further down the field’ in the quest for better understanding of the biologica...